In the search for new materials with tailored properties or novel functionalities, first-principles calculations are playing an increasingly important role. The continuous increase in computing power and significant advancements of theoretical methods and numerical algorithms have pushed the field to a point where first-principles calculations are comparable to experiments in terms of accuracy and greatly surpass them in terms of speed and cost. For more than a century, experimental databases on e.g. structural, thermal, and electronic properties, have been a cornerstone of materials science, and in the past decade, the experimental data have been augmented by an explosion of computational data obtained from first-principles calculations. Strong efforts are currently being focused on storing and organising the computational data in open repositories[1]}, [2]}. Some of the larger repositories, together containing millions of material entries, are the Materials Project[3]}, the Automatic Flow for Materials Discovery (AFLOWLIB)[4]}, the Open Quantum Materials Database (OQMD)[5]}, [6]}, and the Novel Materials Discovery (NOMAD) Repository[7]}.
